1. Field of the Invention
The present invention relates to intake-air cooling type gas turbine power equipment. More particularly, the invention is concerned with intake-air cooling type gas turbine power equipment in which air taken in from the atmosphere is previously cooled and then the cooled air is compressed to produce compressed air, which is then subjected to combustion with a fuel introduced from an external system provided separately from the power equipment, wherein a gas turbine is rotationally driven under the action of the combustion gas of a high temperature resulting from the combustion of the compressed air with the fuel supplied from the external system, and wherein an electric generator operatively coupled to a rotor shaft of the gas turbine is driven through rotation of the rotor shaft for generating electric energy.
Furthermore, the present invention is also concerned with a combined power plant comprised of a combination of the gas turbine power equipment described above and steam turbine power generation equipment which includes a heat-recovery type steam generation boiler in which heat carried by an exhaust gas discharged from the gas turbine is recovered to be utilized for producing a high-temperature/high-pressure steam, a steam turbine driven under the action of the high-temperature/high-pressure steam produced by the heat-recovery type steam generation boiler, and an electric generator operatively coupled to a rotor shaft of the steam turbine, wherein the electric generator is driven through rotation of the rotor shaft for generating electric energy.
2. Description of Related Art
In the conventional gas turbine equipment, air is taken in from the atmosphere for combustion with a fuel within a combustor or for cooling high-temperature components of the gas turbine equipment which are heated to high-temperatures in the course of operation of the gas turbine equipment such as, for example, the main body of the combustor, a tail cylinder, moving blades and stationary blades of the first stage as well as a blade shroud of the gas turbine. The air taken in, i.e., the intake air, is compressed by an air compressor for producing compressed air which is then supplied to the combustor or fed to the aforementioned high-temperature components of the gas turbine equipment for the cooling thereof.
In recent years, with a view to increasing the output of the gas turbine equipment by combusting a greater amount of fuel while increasing the amount of intake air so that a greater amount of air can be used for cooling the high-temperature components of the equipment to thereby reduce heat load thereof for allowing the manufacturing costs of the high-temperature components to be decreased while lengthening the service life thereof, and additionally for the purpose of increasing the inlet temperature of the gas turbine, there has been developed the gas turbine equipment which adopts such an intake air cooling scheme that the air taken in from the atmosphere, i.e., the intake air of the gas turbine, is cooled prior to being supplied to the air compressor, whereon the cooled air is introduced into the gas turbine equipment to thereby increase the effective air quantity, i.e., mass flow of air. Such gas turbine equipment is now attracting public attention.
As one of the means for cooling the intake gas of the gas turbine, there is known a refrigeration system. FIG. 15 is a block diagram showing schematically an arrangement of a conventional refrigeration system. Referring to the figure, reference numeral 101 denotes an electric drive motor, 102 denotes generally a refrigerant compressor driven by the electric motor 101 for compressing a refrigerant vapor to thereby produce a compressed refrigerant vapor, 103 denotes a condenser for cooling the compressed refrigerant vapor with cooling water to condense the compressed refrigerant vapor for thereby producing a liquid-phase refrigerant or refrigerant liquid, 104 denotes a cooling tower for cooling the water which is heated upon cooling of the compressed refrigerant vapor and for feeding back the cooled water to the condenser 103, and 104xe2x80x2 denotes an additional cooling apparatus which is installed separately from the cooling tower 104 and which is destined for cooling the water heated in the condenser 103 and feeding back the cooled water to the latter. Further, reference numeral 105 denotes an evaporator for expanding the refrigerant liquid to transform it to the gas phase, i.e., refrigerant vapor. In that case, water circulating through or between a destined cooling water utilization system (not shown) and the evaporator 105 is deprived of a quantity of heat which corresponds to the latent heat of vaporization of the refrigerant liquid upon expansion thereof. In this way, the circulating water is cooled before being supplied to the destined cooling water utilization system.
In operation, the refrigerant compressor 102 is driven by the electric motor 101 to compress the refrigerant vapor, e.g. vapor of substitute freon, ammonia or the like. The compressed refrigerant vapor is then charged to the condenser 103 where the compressed refrigerant vapor is cooled by the cooling water fed from the cooling tower 104 and/or the additional cooling apparatus 104xe2x80x2 to be condensed to the refrigerant liquid (i.e., liquid-phase refrigerant) which is then fed to the evaporator 105. As mentioned above, water is circulating through the evaporator 105 and the cooling water utilization system (not shown). Consequently, in the evaporator 105, the circulating water is deprived of heat equivalent or corresponding to the latent heat of vaporization of the refrigerant liquid, which is thus vaporized or gasified into the refrigerant vapor. On the other hand, the circulating water deprived of heat equivalent to the latent heat of vaporization of the refrigerant liquid is cooled and fed to the cooling water utilization system or equipment. The refrigerant vapor is supplied to the refrigerant compressor 102 and compressed again to be discharged therefrom as the compressed refrigerant vapor. In this way, a refrigeration cycle is established through the processes of heat transfers to/from the refrigerant and the phase changes or transformations thereof.
In the refrigeration cycle described above, the amount of heat injected into the refrigeration system is a sum of the heat Q1 which is generated upon compression of the refrigerant vapor in the refrigerant compressor 102 which is driven by the electric motor (i.e., heat corresponding to the driving energy for the electric motor) and the heat Q2 which is equivalent to the latent heat of vaporization deprived of the water circulating through the evaporator 105 and the destined cooling water utilization system. On the other hand, heat emanating from the refrigeration system to the ambient is represented by the heat Q3 which is dissipated from the cooling tower 104 and the additional cooling apparatus 104xe2x80x2 when water whose temperature has been raised upon cooling of the compressed refrigerant vapor in the condenser 103 for condensation thereof to the liquid phase is cooled to cold water in the cooling tower 104 and/or the additional cooling apparatus 104xe2x80x2. The heat injected into the refrigeration system and the heat dissipated therefrom must be in equilibrium with each other. In other words, there applies valid the relation given by Q3=Q1+Q2.
FIG. 16 is a block diagram showing a system configuration of a conventional intake-air cooling type gas turbine power equipment in which a refrigeration system is employed. Referring to FIG. 16, reference numeral 106 denotes generally a refrigeration system which includes as major components an electric motor 101, a refrigerant compressor 102, a condenser 103, a cooling tower 104 and an evaporator 105. Reference numeral 107 designates air in the atmosphere. Further, reference numeral 108 denotes a suction chamber into which the air 107 is introduced, 109 designates feed air discharged from the suction chamber, 110 denotes an intake-air cooling chamber for cooling the feed air 109 discharged from the suction chamber 108 through heat exchange with the water cooled by the evaporator 105 of the refrigeration system 106, numeral 111 designates cooled air which is cooled in the intake-air cooling chamber and exhibiting an increased mass flow, 112 denotes an air compressor for transforming the cooled air 111 into compressed air, 113 designates flow of the compressed air compressed by the air compressor (to be utilized for the fuel combustion and for cooling the high-temperature components), 114 designates a fuel supplied from a relevant system (not shown), 115 denotes a combustor for combusting the compressed air 113 and the fuel 114 to thereby produce a high-temperature combustion gas, 116 designates a flow of the high-temperature combustion gas produced by the combustor 115, numeral 117 denotes a gas turbine driven rotationally under the action of the high-temperature combustion gas 116, numeral 118 denotes an electric generator which is operatively coupled to a rotor shaft of the gas turbine and driven through rotation of the rotor shaft for thereby generating electric energy.
In the refrigeration system 106, the refrigerant vapor, e.g. gas of substitute freon, ammonia or the like, is compressed by the refrigerant compressor 102 driven by the electric drive motor 101 and then supplied to the condenser 103 where the compressed refrigerant vapor is cooled by the cold water fed from the cooling tower 104 to be condensed into a refrigerant liquid. The refrigerant liquid undergoes phase-transformation into a refrigerant vapor in the evaporator 105. Upon phase-transformation of the refrigerant liquid in the evaporator 105, heat corresponding to the latent heat of vaporization is deprived of from the water circulating through the evaporator 105 and the intake-air cooling chamber 110, whereby the circulating water is cooled to cold water. On the other hand, air 107 is introduced into the suction chamber 108 from the atmosphere as the gas turbine intake air, and thus the feed air 109 is supplied to the intake-air cooling chamber 110 from the suction chamber 108. In the intake-air cooling chamber 110, the feed air 109 is cooled by the cold water supplied from the evaporator 105, whereby the cooled air 111 is discharged from the intake-air cooling chamber 110. The water whose temperature has been raised upon cooling of the feed air 109 is fed back to the evaporator 105 to be cooled again to serve as the cooling water. The cooled air 111 is fed to the air compressor 112 to be compressed. Thus, the compressed air 113 is discharged from the air compressor 112. A major portion of the compressed air 113 is supplied to the combustor 115 to undergo combustion with the fuel 114 fed from a fuel system (not shown). On the other hand, the remaining part of the compressed air 113 is made use of for cooling the high-temperature components of the gas turbine power equipment. The high-temperature combustion gas 116 which results from the combustion of the fuel 114 with the air in the combustor 115 is fed to the gas turbine 117. Under the action of the high-temperature combustion gas 116, the moving blades mounted fixedly on a rotor (not shown) of the gas turbine 117 are caused to rotate at a high speed. Thus, the electric generator 118 operatively coupled to the rotor shaft of the turbine is rotationally driven for generation of the electric energy.
FIG. 17 is a block diagram showing schematically and generally a system configuration of a combined power plant in which the intake-air cooling type gas turbine power equipment described above by reference to FIG. 16 is combined with a heat-recovery type steam generation boiler and steam turbine power generating equipment with a view to enhancing the efficiency of power generation. In the figure, reference numeral 119 designates an exhaust gas discharged from the gas turbine 117, numeral 120 denotes a heat-recovery steam generation boiler for recovering the heat carried by the exhaust gas 119 to thereby produce a high-temperature/ high-pressure steam by burning a fuel supplied to the boiler, as occasion requires, 121 designates a flow of high-temperature/high-pressure steam 21 produced by the heat-recovery type steam generation boiler 120, numeral 122 denotes a steam turbine rotated under the action of the high-temperature/high-pressure steam 121, numeral 123 denotes an electric generator which is operatively coupled to a rotor shaft of the steam turbine and driven through rotation of the rotor shaft thereof for generating electric energy, 124 designates a flow of exhaust steam discharged from the steam turbine 22, numeral 125 denotes a condenser for condensing the exhaust steam 124 into condensed water, 126 designates a flow of condensed water which is fed back to the heat-recovery type steam generation boiler, and reference symbol P1 denotes a pump for feeding the condensed water 126 to the heat-recovery type steam generation boiler 120. Further, reference numeral 127 designates a flow of exhaust gas discharged from the heat-recovery type steam generation boiler 120, and numeral 128 denotes a smoke stack for discharging the exhaust gas 127 to the atmosphere.
In the figures referenced in the above and in the following description, thick solid lines indicate flows of intake air and exhaust gases in the gas turbine power equipment and the heat-recovery type steam generation boiler, thin solid lines indicate flows of water, refrigerant liquid and the like, and broken lines indicate flows of gases such as steam, refrigerant vapor and the like which circulate through or between the refrigeration system and the steam turbine power generation equipment.
In the intake-air cooling type gas turbine power equipment shown in FIG. 16 as well as in the combined power plant including the combination of the intake-air cooling type gas turbine power equipment, the heat-recovery type steam generation boiler and the steam turbine power generation equipment, as shown in FIG. 17, it is noted that in the refrigeration system designed for cooling the gas turbine intake air as described hereinbefore by reference to the block diagram of FIG. 15 showing the system configuration of the refrigeration system, the heat quantities (Q1+Q2) injected into the refrigerant circulating system of the refrigeration system 106 comprised of the refrigerant compressor 102, the condenser 103, the evaporator 105 and so forth, i.e., the sum of the heat Q1 generated upon compression of the refrigerant vapor by the refrigerant compressor 102 driven by the electric motor 101 and the heat Q2 recovered from the water circulating through the evaporator 105 and the intake-air cooling chamber 110, namely, the heat substantially equivalent to the heat recovered, being deprived of from the feed air 109 (i.e., the intake air of the gas turbine) upon cooling thereof, is transmitted to the water circulating through the condenser 103 and the cooling tower 104 and/or the additional cooling apparatus 104xe2x80x2 to be ultimately dissipated from the cooling tower and/or the other cooling apparatus to the atmosphere, involving thus a heat loss.
In the light of the state of the art described above, it is an object of the present invention to provide intake-air cooling type gas turbine power equipment and a combined power plant comprised of a combination of the intake-air cooling type gas turbine power equipment with a heat-recovery type steam generation boiler and steam turbine power generation equipment in which the heat dissipated to the atmosphere in the conventional intake-air cooling type gas turbine power equipment and the conventional combined power plant is recovered for utilization as heat source for generation of steam in the electric power generation systems, heat source for reheating the intake air of the gas turbine after having been cooled as well as for utilization in a heat utilization system such as a thermal process or processes, an energy service center and/or the like while suppressing the heat loss to a possible minimum.
In view of the above and other objects which will become apparent as the description proceeds, the present invention is directed to improvement of the intake-air cooling type gas turbine power equipment and the combined power equipment including a combination of the intake-air cooling type gas turbine power equipment, a heat-recovery type steam generation boiler and steam turbine power generation equipment.
Thus, according to a general aspect of the present invention, there is provided intake-air cooling type gas turbine power equipment, which includes a refrigeration system comprised of an evaporator and a refrigerant compressor, an intake-air cooling chamber for cooling air taken in from the atmosphere by the evaporator of the refrigeration system, an air compressor for compressing the air cooled in the intake-air cooling chamber to thereby produce compressed air, a combustor for burning a fuel supplied from an external system with the compressed air produced by said air compressor to thereby produce a combustion gas, a gas turbine driven rotationally under the action of the combustion gas produced by the combustor, and an electric generator operatively coupled to a rotor shaft of the gas turbine for generating electric energy, being driven through rotation of the rotor shaft, wherein the refrigerant vapor leaving the evaporator of the refrigeration system is compressed by means of the aforementioned refrigerant compressor to be transformed to a pressurized refrigerant vapor, and wherein heat carried by the pressurized refrigerant vapor is supplied to a heat utilization system to be recovered for utilization.
In a preferred mode for carrying out the present invention, the pressurized refrigerant vapor itself that leaves the refrigerant compressor may be circulated through the heat utilization system so that the heat carried by the pressurized refrigerant vapor can be supplied to the heat utilization system for recovery.
In another preferred mode for carrying out the invention, the refrigeration system may further include a condenser, wherein the pressurized refrigerant vapor leaving the refrigerant compressor is fed to the condenser so that the pressurized refrigerant vapor can undergo heat exchange with a heat transfer medium which circulates through the condenser and the heat utilization system, whereby heat carried by the compressed refrigerant vapor is supplied to the heat utilization system through the medium of the heat transfer medium to be recovered for utilization in the heat utilization system.
In yet another preferred mode for carrying out the invention, a heater for heating and drying the air cooled by the intake-air cooling chamber may be disposed within the intake-air cooling chamber at a cooled-air discharge side thereof, and the heat carried by the pressurized refrigerant vapor leaving the refrigerant compressor may be utilized as a source of heat for the heater.
According to another aspect of the invention, there is provided a combined power plant, which includes intake-air cooling type gas turbine power equipment, a heat-recovery type steam generation boiler, steam turbine power generation equipment and a condenser. In the combined power plant, the intake-air cooling type gas turbine power equipment includes a refrigeration system comprised of an evaporator and a refrigerant compressor, an intake-air cooling chamber for cooling air taken in from the atmosphere by the evaporator of the refrigeration system, an air compressor for compressing the air cooled by the intake-air cooling chamber to thereby produce compressed air, a combustor for burning a fuel supplied from an external system with the compressed air produced by said air compressor to thereby produce a combustion gas, a gas turbine driven rotationally under the action of the combustion gas produced by the combustor, and an electric generator operatively coupled to a rotor shaft of the gas turbine for generating electric energy, being driven through rotation of the rotor shaft. The heat-recovery type steam generation boiler mentioned above serves for recovering a quantity of heat carried by the combustion exhaust gas discharged from the gas turbine of the gas turbine power equipment. On the other hand, the steam turbine power generation equipment mentioned above includes a steam turbine driven rotationally under the action of a high-temperature/high-pressure steam produced by the heat-recovery type steam generation boiler and an electric generator operatively coupled to a rotor shaft of the steam turbine for generating electric energy, being driven through rotation of the rotor shaft. The condenser mentioned above serves for condensing to water (condensed water) the steam discharged from the steam turbine of the steam turbine power generation equipment. In the combined power plant described above, the condensed water is used in the evaporator of the refrigeration system and the refrigerant vapor generated by the evaporator is pressurized by the refrigerant compressor. Heat carried by the pressurized refrigerant vapor is utilized for heating feed water of the heat-recovery type steam generation boiler utilized for recovery by the steam turbine as power.
In a preferred mode for carrying out the invention in conjunction with the combined power plant described above, the evaporator of the refrigeration system may be disposed within the intake-air cooling chamber of the intake-air cooling type gas turbine power equipment for cooling the intake air, and the refrigerant vapor leaving the evaporator may be compressed by the refrigerant compressor to thereby be transformed to a pressurized refrigerant vapor.
According to yet another aspect of the invention, there is provided a combined power plant, which includes intake-air cooling type gas turbine power equipment, a heat-recovery type steam generation boiler, steam turbine power generation equipment and a condenser. In the combined power plant, the intake-air cooling type gas turbine power equipment includes a refrigeration system comprised of an evaporator and a refrigerant compressor, an intake-air cooling chamber for cooling air taken in from the atmosphere by the evaporator of the refrigeration system, an air compressor for compressing the air cooled by the intake-air cooling chamber to thereby produce compressed air, a combustor for burning a fuel supplied from an external system with the compressed air produced by said air compressor to thereby produce a combustion gas, a gas turbine driven rotationally under the action of the combustion gas produced by the combustor, and an electric generator operatively coupled to a rotor shaft of the gas turbine for generating electric energy, being driven through rotation of the rotor shaft. The heat-recovery type steam generation boiler mentioned above serves for recovering a quantity of heat carried by the combustion exhaust gas discharged from the gas turbine of the gas turbine power equipment On the other hand, the steam turbine power generation equipment mentioned above includes a steam turbine driven rotationally under the action of a high-temperature/high-pressure steam produced by the heat-recovery type steam generation boiler and an electric generator operatively coupled to a rotor shaft of the steam turbine for generating electric energy, being driven through rotation of the rotor shaft. The condenser mentioned above serves for condensing to water (condensed water) the steam discharged from the steam turbine of the steam turbine power generation equipment. In the combined power plant described above, refrigerant vapor discharged from the evaporator of the refrigeration system is pressurized to a pressurized refrigerant vapor by the refrigerant compressor, the pressurized refrigerant vapor being fed to the condenser of the refrigeration system where the pressurized refrigerant vapor undergoes heat exchange with the condensed water produced by the condenser to thereby heat the condensed water while the pressurized refrigerant vapor itself is condensed to a refrigerant liquid (liquid-phase refrigerant) to be fed back to the evaporator, whereas the condensed water as heated is fed to the heat-recovery type steam generation boiler.
In a further preferred mode for carrying out the invention in conjunction with the combined power plant described just above, the evaporator of the refrigeration system may be disposed within the intake-air cooling chamber of the intake-air cooling type gas turbine power equipment for cooling the intake air, and the refrigerant vapor leaving the evaporator may be compressed by the refrigerant compressor to thereby be transformed to the pressurized refrigerant vapor.
As mentioned previously, in the conventional intake-air cooling type gas turbine power equipment as well as the conventional combined power plant in which the intake-air cooling type gas turbine power equipment is employed, the heat recovered by the evaporator upon cooling of the intake air and the heat generated in the course of operation of the refrigerant compressor in the refrigeration system are dissipated to the atmosphere from the cooling tower and/or other cooling apparatus, involving the heat loss. By contrast, in the intake-air cooling type gas turbine power equipment and the combined power plant employing the same according to the present invention, the heat mentioned above can be utilized as a heat source for reheating the intake air for the gas turbine intake air and/or as heat source for producing steam and for heating feed water for an external electric power generation system and/or can be recovered for utilization in an external heat utilization system such as thermal processes, energy service center or the like. Thus, occurrence of heat loss can be suppressed to a possible minimum.
At this juncture, description will be made of the refrigeration system employed according to the present invention. Assuming that water/steam is to be used as the refrigerant, heat substantially equivalent to heat of vaporization of water is deprived of from the ambient or a heat transfer medium upon expansion of water under high vacuum e.g. of 6.5 mmHg, whereby the ambient temperature is lowered or the heat transfer medium is cooled. The refrigerant water itself transforms into steam (gas) which undergoes compression work to thereby be compressed and resumes the phase of water through condensation. The liquid-phase water or condensed water is again expanded under high vacuum. In this manner, a Rankine cycle or so-called heat pump in which expansion/compression/condensation process is repeated is carried out, which provides the fundamental basis for the refrigeration.
By using the refrigeration system for cooling the intake air of the gas turbine, the intake air temperature of e.g. 30 C. can be lowered to a level within a range of 10 C. to 15 C. When the temperature of the intake air of the gas turbine is lowered, the mass flow of the intake air to be consumed in the combustion with the fuel and to be used for cooling the high-temperature components will necessarily increase. Thus, the output of the gas turbine can be increased, while cooling of the high-temperature components can be realized with enhanced efficiency.
In addition to the refrigeration system where the water/steam is used as the refrigerant, there exists refrigeration systems in which dedicated refrigerant such as substitute freon, ammonia or the like is employed. Further, for driving the refrigerant compressor of the refrigeration system, there may be adopted electric motor drive, gas or steam turbine drive, engine drive by diesel engine or gasoline engine, single-shaft type combined cycle drive or the like. The refrigeration system may be realized by a given one of various combinations of the refrigerating machines, refrigerants and the drives mentioned above.
The above and other objects, features and attendant advantages of the present invention will more easily be understood by reading the following description of the preferred embodiments thereof taken, only by way of example, in conjunction with the accompanying drawings.